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This paper describes an in-cylinder lean-rich combustion (no-post-injection for rich) switching control approach for modern diesel engines equipped with exhaust-treatment systems. No-post-injection rich combustion is desirable for regeneration of engine exhaust-treatment systems thanks to its less fuel penalty compared with regeneration approaches using post-injections and / or in-exhaust injections. However, for vehicle applications, it is desirable to have driver-transparent exhaust-treatment system regenerations, which challenge the in-cylinder rich-lean combustion transitions. In this paper, a nonlinear in-cylinder condition control system combined with in-cylinder condition guided fueling control functions were developed to achieve smooth in-cylinder lean-rich switching control at both steady-state and transient operation. The performance of the control system is evaluated on a modern light-duty diesel engine (G9T600).

Antilock brake systems for air braked vehicles have been growing in popularity in Great Britain and Europe and appear to be candidates for extensive use in the United States as well. Previous mandated use in the United States during the 1970's was not successful, in part because of reliability problems, and the National Highway Traffic Safety Administration (NHTSA) has decided that a thorough evaluation of air brake antilock systems is necessary prior to any decision about the appropriateness of future mandatory use in the United States. This paper describes the electronic data collection equipment and processing techniques which are being used in the NHTSA 200 truck evaluation project. Detailed maintenance histories for each truck are being recorded manually as a separate segment of the project. An average of 6 to 7 megabytes of data per week is being collected in the various cities in which fleets are operating test vehicles.

There is growing interest in additive manufacturing technologies for prototype if not serial production of complex internal combustion engine components such as cylinder heads and pistons. In support of this general interest the authors undertook an experimental bench test to evaluate opportunities for cooling jacket improvement through geometries made achievable with additive manufacturing. A bench test rig was constructed using electrical heating elements and careful measurement to quantify the impact of various designs in terms of heat flux rate and convective heat transfer coefficients. Five designs were compared to a baseline - a castable rectangular passage. With each design the heat transfer coefficients and heat flux rates were measured at varying heat inputs, flow rates and pressure drops. Four of the five alternative geometries outperformed the baseline case by significant margins.

A new diesel engine system adopting alternative combustion with rich and near rich combustion, and an airflow-dominant control system for precise combustion control was used with a 4-way catalyst system with LNT (lean NOx trap) to achieve Tier II Bin 5 on a 2.2L TDI diesel engine. The study included catalyst temperature control, NOx regeneration, desulfation, and PM oxidation with and without post injection. Using a mass-produced lean burn gasoline LNT with 60,000 mile equivalent aging, compliance to Tier II Bin 5 emissions was confirmed for the US06 and FTP75 test cycles with low NVH, minor fuel penalty and smooth transient operation.

An airflow-dominant control system was developed to provide precise engine and exhaust treatment control with low air fuel ratio alternative combustion. The main elements of the control logic include a real-time state observer for in-cylinder oxygen mass estimation, a simplified packaging scheme for all air-handling and fueling parameters, a finite state machine for control mode switching, combustion control models to maintain robust alternative combustion during transients, and smooth rich/lean switching during lean NOx trap (LNT) regeneration without post injection. The control logic was evaluated on a passenger car equipped with a 4-way catalyst system with LNT and was instrumental in achieving US Tier II Bin 5 emission targets with good drivability and low NVH.

This paper describes a hybrid robust nonlinear control approach for modern diesel engines running low temperature combustion and conventional diesel combustion modes. Using alternative combustion modes has become a promising approach to reduce engine emissions. However, due to very different in-cylinder conditions and fueling parameters for different combustion modes, control of engines operating multiple combustion modes is very challenging. It becomes difficult for conventional calibration / mapping based approaches to produce satisfactory results in terms of engine torque responses and emissions. Advanced control techniques are then demanded to accomplish the tasks. An innovative hybrid control system is designed to track different key engine operating variables at different combustion modes as well as avoid singularity which is inherent for turbocharged diesel engines running multiple combustion modes.

The classical approach to prepare engine exhaust emissions control systems for evaluation and certification is to condition the fresh parts by aging the systems on an engine/dynamometer aging stand. For diesel systems this can be a very lengthy process since the estimated service life of the emissions control systems can be several hundred thousand miles. Thus full useful life aging can take thousands of engine bench aging hours, even at elevated temperatures, making aging a considerable cost and time investment. Compared to gasoline engines, diesel engines operate with very low exhaust gas temperatures. One of the major sources of catalyst deactivation is exposure to high temperature [ 1 ].

For transmission suppliers tooled primarily for producing manual transmissions, retrofitting a manual transmission with actuators and a controller is business viable. It offers a low cost convenience for the consumer without losing fuel economy when compared to torque converter type automatics. For heavy duty truck fleets even the estimated 3% gain in fuel economy that the Automated Manual Transmission (AMT) offers over the manual transmission can result in lower operational costs. This paper provides a case study using a light duty transmission retrofitted with electric actuation for gears and the clutch. A high level description of the control algorithms and hardware is included. Clutch control is the most significant component of the AMT controller and it is addressed in detail during operations such as vehicle launch from rest, launch from coast and launch on grades.

Cabin air quality is of continuing importance [1]. Contamination of air with particulates or vapors has the potential of affecting the health of passengers and flight crew. Therefore, measures are required to maintain acceptable levels of cabin air quality. One potential source of cabin air contamination is lubricating oils used in the engines. Type II oils are required for the main engines, but Type I or Type II oils can be used for the APU, with Type I recommended by some engine manufacturers for its cold-start properties. Southwest Research Institutes (SwRI®) Department of Emissions Research used an internally developed analytical method called Direct Filter Injection/Gas Chromatograph (DFI/GC™) to analyze for volatile fractions of lubricating oil contaminants on Environmental Control System (ECS) components. Samples of two standard Type II aviation turbine lubricating oils were analyzed with the DFI/GC™ method and their spectra examined.

This paper describes the findings of a laboratory effort to demonstrate improved automotive exhaust emission control with a cold-start hydrocarbon collection system. The emission control strategy developed in this study incorporated a zeolite molecular sieve in the exhaust system to collect cold-start hydrocarbons for subsequent release to an active catalytic converter. A prototype emission control system was designed and tested on a gasoline-fueled vehicle. Continuous raw exhaust emission measurements upstream and downstream of the zeolite molecular sieve revealed collection, storage, and release of cold-start hydrocarbons. Federal Test Procedure (FTP) emission results show a 35 percent reduction in hydrocarbons emitted during the cold-transient segment (Bag 1) due to adsorption by the zeolite.

In this study, the criteria pollutant emissions from a light duty vehicle equipped with Dedicated EGR® technology were compared with emissions from an identical production GDI vehicle without externally cooled EGR. In addition to the comparison of criteria pollutant mass emissions, an analysis of the gaseous and particulate chemistry was conducted to understand how the change in combustion system affects the optimal aftertreatment control system. Hydrocarbon emissions from the vehicle were analyzed usin g a variety of methods to quantify over 200 compounds ranging in HC chain length from C1 to C12. The particulate emissions were also characterized to quantify particulate mass and number. Gaseous and particulate emissions were sampled and analyzed from both vehicles operating on the FTP-75, HWFET, US06, and WLTP drive cycles at the engine outlet location.

This paper discusses the implications of computerizing the SAE #2 clutch friction durability tests that General Motors Corporation and Ford Motor Company require for automatic transmission fluid certification. There are three reasons for this paper. 1) Friction durability testing is a significant part of a much larger battery of tests needed to qualify a fluid. 2)There have been recent modifications concerning computerization of both the Ford and GM tests. 3) Because there are only two OEM qualified testing facilities, the details of certain testing intricacies in the areas of data acquisition, reduction and reporting may not be as understood as well as in other areas of automotive-based standardized testing. Formulators of automatic transmission fluid need to be aware of all details surrounding the collection and evaluation of the data that will result in the final test report.

Development of a state of the art, electronically controlled natural gas-fueled engine is detailed in this paper. The engine is a lean burn, turbochargedaftercooled engine controlled by a full authority electronic control system. This system controls fuel metering, spark timing, boost pressure, throttle position, and governing. The control system features closed-loop/adaptive-learn fuel control with feedback provided by a universal exhaust gas oxygen sensor. The development of the engine included development of the control system and other engine components, as well as a substantial amount of steady-state and transient control system calibration work. This effort led to a final engine calibration which provides good efficiency and transient response while meeting CARB ULEV emissions levels.

Because of its dominant role in diesel engine performance and emissions, the fuel injection process has become an area of very active research and development. It is now clear that location, shape, rate of development, and mass flow distribution within each fuel jet are all important in controlling fuel air mixing, wall interactions, combustion rate, and the resulting levels of emissions. The objective of this project was to develop an instrument for measurement of the instantaneous fuel mass and momentum distribution in the jets issuing from diesel injection nozzles. The goal was to develop an instrument concept that can be used in the laboratory for fundamental measurements, as well as a quality control system for use in manufacture of the injection nozzles. The concept of the instrument is based on the measurement of the instantaneous momentum of the fuel jet as it impacts on a surface equipped with pressure sensitive elements.

Improvements in several areas are required to convert current technology light-duty vehicles into low-emissions vehicles suitable for meeting California's Ultra-Low Emissions Vehicle (ULEV) standards. This paper discusses one of those areas, the engine and aftertreatment control system algorithms. The approach was to use model-based air and fuel flow calculations to maintain accurate air-fuel ratio control, and to interface the aftertreatment requirements with engine air-fuel ratio control during the cold- and hot-start parts of the cycle. This approach was applied to a 1993 Ford Taurus operating on Ed85 (85% denatured alcohol, 15% gasoline).

The effect of humidity on the lean misfire limit and emissions from a lean burn, natural gas engine is described in this paper, along with a description of a practical humidity compensation method for incorporation into an electronic control system. Experiments to determine the effects of humidity on the lean limit and emissions are described. Humidity increases were shown to decrease the rate of combustion, reduce NOx emissions, and increase the levels of unburned hydrocarbon (HC) and carbon monoxide (CO) emissions. Data and calculations are also presented which demonstrate that increases in humidity will cause enleanment in a typical closed loop control system utilizing a universal exhaust gas oxygen (UEGO) sensor. A prototype system for humidity sensing and subsequent compensation based on these findings was implemented, and the system was found, through additional testing, to compensate for humidity very effectively.

Research has shown that there are many factors that affect the long-term performance of nitrogen oxides (NOx) control systems used in diesel engine applications. However, if the NOx emissions can be accurately monitored, it might be possible to restore performance by making adjustments to the control systems. This paper presents results from a study that tested the durability of 25 NOx sensors exposed to heavy-duty diesel exhaust for 6,000 hours. The study, conducted by the Advanced Petroleum-Based Fuels - Diesel Emission Controls (APBF-DEC) project, tested the sensors at various locations in the exhaust stream.

Southwest Research Institute® (SwRI®) has developed electronic fuel injection (EFI) systems to be used on air-cooled motorcycle applications. In order to explore differences in application requirements between large and small displacement motorcycles, a large twin-cylinder, four-stroke, air-cooled motorcycle, and a small single cylinder, four-stroke, air-cooled motorcycle were utilized. The primary objectives of this study were to meet current and future emissions regulations for motorcycle exhaust emissions, to raise fuel economy, and to improve overall engine performance. The EFI development required baseline testing, control system setup, design of intake system components, installation of sensors and control unit, fuel system integration, steady-state and transient calibration, fuel consumption development, emissions development, performance improvement, and acceleration testing.

Tremendous amount of useful information can be extracted from the cylinder pressure signal for engine combustion control. However, the physical cylinder pressure sensors are undesirably expensive and their health need to be monitored for fault diagnostic purpose as well. This paper presents the results of the development of a virtual cylinder pressure sensor (VCPS) with individual variable-oriented independent estimators. Two neural network-based independent cylinder pressure related variable estimators were developed and verified at steady state. The results show that these models can predict the variables correctly compared with the extracted variables from the measured physical cylinder pressure sensor signal. Good generalization capabilities of the developed models are observed in the sense that the models work well not only for the training data set but also for the new inputs that they have never been exposed to before.

A unique and attractive variator mechanism has been developed by Turbo Trac, Inc. and Southwest Research Institute (SwRI) for initial use in a heavy duty diesel truck application. High efficiency levels have been predicted with analytical models and confirmed with actual test data. Further, this variator incorporates a very stable and simple control system and has extremely high torque capacity. The prototype of the variator mechanism has also been configured with a modified Allison 650 series transmission for use as a series application in a Peterbilt truck, the final configuration will be a split power design. The setup includes a preliminary control system that allows for highway driving. It is emphasized, however, that Allison did not contribute to this design or any of the content of this paper.